Fig 3. Aβ42-induced proteasome inhibition is associated with a delayed, inverse effect on CatB activity.
Hippocampal slice cultures were treated daily with vehicle for 6 days (0-day control group) or with pre-aggregated Aβ42 for 4–6 days, staggering the treatments in order for same-day harvesting of slice groups of 7–9 each. Proteasome activity (gray plot of mean Vmax/s ± SEM; ANOVA: p<0.01) and cathepsin B activity (black plot of mean fluorometric units ± SEM; ANOVA: p<0.01) were measured in equal protein aliquots from the same samples (a). The time-course samples were also assessed for 55–70-kDa pTau-Ser199/202 and actin in order to plot the within-sample ratios between the immunoreactivity levels (b; mean ± SEM). Tukey post hoc tests compared to vehicle-treated slices: **p<0.01, ***p<0.001.